Re: Request to drop daft GNU extension

[Neil Booth <NeilB at earthling dot net>]

Martin v. Loewis wrote:-

> I'm in favour of dropping it, but I would really like to see the C99
> version as a replacement, not an ongoing support for the GNU macro
> varargs feature. If possible, the preprocessor should detect that a
> certain expansion has a different meaning under GNU C and C99, issue a
> warning, and use the C99 meaning. There should be an option to restore
> the GNU C meaning.

That's ongoing support, though, no?  Or do you mean with the intent of
dropping it altogether in some later version?

> 
> > #define eprintf(format, args...) fprintf (stderr, format , ## args)
> 
> In C99, this would be written as
> 
> #define eprintf(format, ...) fprintf (stderr, format __VA_ARGS__)
> 
> Right?

Yes, if you're happy writing something like

eprintf ("string", )

for the empty case.  Alternatively

#define eprintf(...) fprintf (stderr, __VA_ARGS__)

doesn't require that extra comma in the invocation.  But then

eprintf()

is not a cpp error, and you'd have to wait for the front end to issue
an error.

Neil.